Patent Application
20080276922
This invention relates generally to structures that may be built using masonry blocks. More particularly, this invention relates to an apparatus for and method of dressing externally viewable surfaces of masonry blocks used to construct mortarless retaining walls.
Retaining walls are widely used in a variety of landscaping applications. Typically, they are used to maximize or create level areas and also to reduce erosion and slumping. They may also be used in a purely decorative manner. In the past, retaining wall construction was labor intensive and often required the skills of trained tradespeople such as masons and carpenters. More recently, retaining wall construction has become significantly simplified with the introduction of self-aligning, modular molded blocks of concrete that may be stacked in vertical or offset courses without the use of mortar or any special skills. These blocks are available in a variety of shapes and sizes and a great many of them even allow a retaining wall to be curved or sinuous, so that it may be constructed circumjacent a tree, or parallel to a meandering pathway, for example.
Initially, these blocks were available in a limited number of sizes, shapes and textures. However, as the aforementioned blocks have become more and more popular, a greater variety of blocks of different styles have become available to the consumer. A particular style of block that is increasing in popularity is the rustic or weathered look. Rustic or weathered look blocks are desirable for several reasons. First, they convey the impression of craftsmanship that is nowadays frequently absent. Second, their time worn appearance conveys a sense of security and stability. And third, they are visually pleasing to an observer. With rustic or weathered blocks, it is possible to form structures that give the impression that they were constructed by artisans of a bygone era. These styles of blocks are particularly useful in restorative or rehabilitation work, or where certain stylistic and structural standards must be maintained.
A variety of approaches have been used to create rustic blocks. The most elementary and straightforward approach is to take a molded block and hand dress or roughen the surface. This approach has several drawbacks that are difficult to overcome. One, it significantly adds to the cost of the product because it is necessary to hire a person (or more likely, a crew of people) to perform this additional task. And, it may also be necessary to train or otherwise educate a person to perform such a task. Two, it increases the time necessary to produce such a product because hand dressing requires additional, time-consuming steps. Whether at the factory or at a job-site, each block must now be moved to a work station where it is hand dressed prior to use.
Since it is prohibitively expensive to hand dress block, alternative approaches to forming rustic blocks have been attempted. One approach has been to provide a patterned mold that is able to simulate a rustic surface. This approach has its drawbacks. One, It takes time and efforts to create and fabricate a mold. Two, the process of molding a block includes additional time consuming steps. Three, the process is limited to the formation of a particular style of block. And while it eliminates the step of hand dressing, a user is more-or-less stuck with the product as it comes from the mold. Any modification thereafter would defeat the purpose of such a block. And four, the molded surface does not have the appearance of hand dressing that is desired by the increasingly discerning and sophisticated customer.
Another approach is to take a molded block and place it in a rotatable container that tumbles it about (preferably, with other blocks or suitable material). This approach is much more cost effective and efficient that that of hand dressing each block. And, as with hand dressed blocks, each block so produced has a distinctive character. This approach, however, has a major drawback. The problem is that as a block is being tumbled, all of the exterior surfaces are being ground down. While this is a desirable result where the externally viewable surface of the block is concerned, it is an undesirable result for the remaining exterior surfaces of the block, particularly at the sides where the ability of adjacent blocks to be positioned flush against each other in a sealing relation may be compromised. Thus, instead of having linear side surfaces in sealing relation between adjacent blocks, there are now jagged side surfaces that form gaps or spaces therebetween. These gaps allow back-fill material to filter therethrough and accumulate in front of the structure. This is often exacerbated by rainfall that mixes with and transports particulate matter through the gaps, which may stain or otherwise leave residue on lower courses blocks that detracts from the overall appearance of the structure.
Another approach is to form them during the manufacturing process. This is most often accomplished by casting two blocks together in a single mold and splitting them apart along a predetermined plane. This creates two blocks, each with a front face that has the appearance of a natural split rock. A drawback with this approach is that blocks produced in this manner, while attractive, do not convey the impression that they were entirely hand worked. At best, they suggest that the blocks were broken away from a parent material and then machine dressed to predetermined dimensions. Thus, they have tight, thin, straight joints and, when assembled together, give the impression of a unitary structure having a textured surface.
Efforts to create a more realistic looking rustic block based on the aforementioned split-face block have taken several approaches. One approach is to hand dress selected portions of a block. This approach is less labor intensive than hand dressing the entire surface of a block as previously mentioned, but it still has the same aforementioned drawbacks—though to a lesser degree. One, it significantly adds to the cost of the product because it is necessary to hire a person (or more likely, a crew of people) to perform this additional task. And, it may also be necessary to train or otherwise educate a person to perform such a task. Two, it increases the time necessary to produce such a product because hand dressing requires additional, time-consuming steps. Whether at the factory or at a job-site, each block must now be moved to a work station where it is hand dressed prior to use.
Yet another approach uses flails to modify the externally viewable surfaces of blocks. Typically, the flails comprise short sections of chain one end of which is affixed about the perimeter of a rotatable element, the other end of which is attached to a steel head. In operation, the steel heads of the flails strike the entire front surface of a block as they are swung about by the rotatable element. While the flails produce acceptable results, there are several drawbacks. One, in order for the flails to operate at maximum efficiency, they must be swung about at a high rotational speed. This presents potentially dangerous condition, for if a flail were to break loose from the rotating element, they could easily injure people within the vicinity. Two, single or multiple links of a chain could break loose. This means that the flails must be inspected periodically to ensure that there are no cracks or damaged links that may lead to failure. The result is down time and loss of production. Three, as the flails strike a surface, they tend to crush or blast away the material away and form large amounts of dust. This presents health concerns such as ingestion, inhalation and sanitation. Moreover, such dust may create dangerous operating conditions by reducing visibility within the immediate vicinity or by settling upon equipment and obscuring essential components such as gauges or warning stickers. And, airborne dust also creates the potential for explosions initiated by sparks or electrical discharges. Four, flails are noisy, and people in the vicinity may be adversely affected by prolonged exposure to the noise associated with operation of such a device—even with the provision of ear protection.
There is a need for a masonry block that, when assembled together with other masonry blocks to form a structure, creates the impression that craftsmen using hand tools constructed the structure. There is also a need for a masonry block that may have marginal areas of its externally viewable surface dressed and still be able to be combined with other masonry blocks to form joints that effectively prevent passage of particulate matter therebetween.
There is also a need for an apparatus that is able to dress externally viewable surfaces of blocks without altering the remaining surfaces of the blocks, and do so in a manner that minimizes the formation of undue amounts of dust. There is yet another need for an apparatus that may be adjusted to accommodate masonry blocks having different dimensions, and which may be configured and arranged to dress only marginal areas of externally viewable surfaces of masonry blocks. There is yet another need for an apparatus that is able to dress a plurality of masonry blocks in an expedient and efficient manner.
And, there is a need for a method by which rustic masonry blocks may be fabricated.
The present invention comprises an apparatus for working externally viewable surfaces of masonry blocks in such a manner so that they appear to have been hand dressed. For purposes of this application, the term masonry block (or block) is intended to include any naturally occurring material, manmade material, molded cementitious block, natural and artificial stone or like material that may be used for buildings, indoor walls, partitions, facades, retaining walls, walkways, or other similar structures, with or without mortar. Preferably, the apparatus comprises a first station and a second station. The first station includes a pair of cylindrically shaped, rotatable chippers with each chipper having a rotational axis and a plurality of outwardly extending teeth randomly disposed thereabout. The chippers are adjustably arranged so that the rotational axes are parallel to and spaced apart from each other so that the outwardly extending teeth of the chippers do not interfere with each other during operation of the first station.
The first station also includes an adjustable block support that is positioned adjacent the chippers; preferably in an orthogonal relation relative to the rotational axes of the chippers. The support is configured and arranged to permit constrained movement of a block towards and away from the rotatable chippers to enable opposing, marginal areas of the externally viewable surface of a block to be simultaneously worked. In operation, the teeth of the chippers work or knap the opposing marginal areas of the externally viewable surface by percussively impacting and fracturing a block in a random manner. This produces an erose or jagged surface that is indicative of a rustic style block. For purposes of this application the term tooth (and its plural form, teeth) is intended to include any protrusion, projection, tooling or other such structure capable of dressing or knapping portions of a masonry block. Also for purposes of this application the term marginal area includes not only the areas adjacent the periphery of the externally viewable surface of a block but also other marginal areas form, for example, at the intersection formed by facets in a block having a non-planar externally viewable surface.
The second station includes another pair of cylindrically shaped, rotatable chippers with each chipper having a rotational axis and a plurality of outwardly extending teeth randomly disposed thereabout. As with the pair of chippers at the first station, the chippers in the second station are adjustably arranged so that the rotational axes are parallel to and spaced apart from each other so that the outwardly extending teeth of the chippers do not interfere with each other during operation.
The second station also includes an adjustable block support. As with the support at the first station, this support is positioned adjacent the chippers. However, instead of being positioned orthogonal to the rotational axes of the chippers as with the first station, this support is positioned so that it is collaterally aligned with and between the rotational axes of the chippers at the second station. The support is configured and arranged to permit constrained movement of a block collaterally with respect to the rotational axes of the rotatable chippers to enable opposing, marginal areas of the externally viewable surface of a block to be simultaneously worked. In operation, the teeth of the chippers work or knap the opposing marginal areas of the externally viewable surface by percussively impacting and fracturing a block in a random manner. This produces an erose or jagged surface that is indicative of a rustic style block. Thus, by using the first and second stations, it is possible to dress a plurality of marginal areas of an externally viewable surface of a masonry block in an efficient and expedient manner.
The apparatus may be used with a wide variety of preformed masonry blocks having a wide variety of sizes and surface textures. With the apparatus, it is possible to work a single or multiple areas of an exterior surface. For example, it is possible to work only the vertical margins of a block. Or, it is possible to work only the horizontal margins of a block. Or, it is even possible to work only one vertical margin and one horizontal margin. In that vein, it is envisioned that the apparatus may even work marginal areas that are not at the periphery of an externally viewable surface.
Preferably, the apparatus is used in conjunction with masonry blocks that have a split-face or roughened surface, so that the entire externally viewable surface of the dressed block appears rustic.
It is an object of the present invention to provide an apparatus that is able to dress marginal areas of a masonry block.
Another object of the present invention is to provide a method by which a masonry block may be dressed.
Yet another object of the invention is to form erose marginal areas that simulate hand dressing.
It is another object of the present invention to increase the speed at which rustic masonry blocks may be fabricated by providing a plurality of chipper units.
It is yet another object of the invention to provide a masonry block that, after dressing, is able to substantially contact an adjacent masonry block and effectively prevent particulate matter from passing therebetween.
A feature of the present invention is the use of chipper having a body with a rotational axis, about which a plurality of teeth are randomly disposed.
Another feature of the invention is that the components of the apparatus may be adjusted to provide different knapping depths, or to accommodate differently sized blocks.
An advantage of the present invention is that the randomly disposed teeth impact a marginal area being worked at a relatively slow speed.
Another advantage of the present invention is that formation of dust during the knapping process is minimized.
An advantage of the present invention is that the apparatus is able to accommodate a variety of differently shaped blocks.
Another advantage of the invention is that a plurality of dressed blocks may be dressed in an expedient and efficient manner.
These and other objectives, features and advantages of the invention will appear more fully from the following description, made in conjunction with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views. And, although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention, which may be embodied in other specific structure. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
With reference to
Generally, the first station 14 comprises first and second chippers 20, 30 and a support 50. More specifically, the first chipper 20 includes a body 22 with a rotational axis 24 and a plurality of outwardly extending teeth 26 randomly disposed thereabout. The second chipper 30 includes a body 32 with a rotational axis 34 and a plurality of outwardly extending teeth 36 randomly disposed thereabout. The first and chipper bodies 22, 32 are cylindrically shaped and have a diameter of around 1.0-4.0 inches (2.54-10.00 cm), respectively, and a preferred diameter of around 2.0-3.0 inches (5.00-7.50 cm). The first and second chippers 20, 30 may be operatively connected to separate motive sources, or preferably a single motive source such as a hydraulic motor and a drive chain (not shown) that rotate the chippers 20, 30 at a rate of around 100-500 revolutions per minute (rpm) and preferably around 200-375 rpm. As will be appreciated, the rotational directions of the first and second chippers 20, 30 are chosen to so that the chippers work in opposition to each other.
A support 50 is positioned adjacent the first and second chippers 20, 30 in an orthogonal position relative to the rotational axes of the first and second chippers 20, 30. The support 50 is configured to allow a block to move in a constrained manner. This may be done with the provision of adjustable fences 52, 54 and an adjustable stop 56. The stop 56 may be provided with a biasing element 58 that assists in disengaging a block from contact with the chippers 20, 30. While this embodiment uses fences and a stop to direct the movement of a block with respect to the chippers 20, 30 other arrangements are possible. For example, the support 50 may be provided with a channel or aperture (not shown) that is configured to receive an indexing projection of a block (See, for example, the projections depicted in the blocks of
As with the first station, the second station 16 generally comprises a pair of third and fourth chippers 60, 70 and a support 90. More specifically, the third chipper 60 includes a body 62 with a rotational axis 64 and a plurality of outwardly extending teeth 66 randomly disposed thereabout. The fourth chipper 70 includes a body 72 with a rotational axis 74 and a plurality of outwardly extending teeth 76 randomly disposed thereabout. The third and fourth 62, 72 are also cylindrically shaped. They are larger in diameter than the first and second chippers, however, and have a diameter of around 4.0-6.0 inches (10.00-15.25 cm), respectively, and a preferred diameter of around 4.5-5.5 inches (11.40-14.00 cm). The third and fourth 60, 70 are also operatively to motive sources, or preferably connected to a motive source such as a hydraulic motor and a drive chain (not shown) that rotate the chippers 60, 70 at a rate of around 10-200 revolutions per minute (rpm) and preferably around 50-150 rpm. As will be appreciated, the rotational directions of the first and second chippers 60, 70 are chosen to so that the chippers work in opposition to each other so that the forces of impact tend to cancel each other out.
A support 90 is positioned adjacent the third and fourth chippers 60, 70 collaterally and between the rotational axes 64, 74 of third and fourth chippers 60, 70. The support 90 is configured to allow a block to move in a constrained manner. This may be done with the provision of an adjustable fence 92 (See,
With reference to
As will be appreciated, the speed at which the block 100 is moved relative to the chippers 60, 70 is an additional variable that contributes to the distinctive surfaces that may be achieved with the apparatus. For example, if the block 100 is moved rapidly relative to the chippers, the chipper teeth will impact the block a fewer number of times than if the block 100 is moved slowly relative to the chippers.
Referring to
In conjunction with the chippers, it is envisioned that the block dressing apparatus may be provided with static or movable brush-like elements (not shown) that finish a block by blending impact marks left by the teeth with the rest of the externally viewable surface. Alternatively, the chipper bodies themselves may include brush elements thereon (also not shown) so that they are able to dress and finish a portion of an externally viewable surface of a block.
Referring now to
Each side 122, 124 includes block contacting surfaces 126, 128, and 130, 132, respectively. And, each side 122, 124 also includes splitting or fracture relief notches 134, 136, and 138, 140, respectively. The block 100 also includes an externally viewable surface 142 having a central area 144 (generally indicated by a dashed line) with opposing marginal areas 146, 148 and 150, 152. It will be appreciated that the central area 144 will vary depending upon the particular configuration of the block and the extent to which the block is to be dressed. Referring to
The block depicted in
Referring to
Referring now to
Each side 182, 184 includes block contacting surfaces 186, 188, and 190, 192, respectively. And, each side 182, 184 also includes splitting or fracture relief notches 194, 196, and 198, 200, respectively. The block 160 includes an externally viewable surface 202 having a central area 204 (generally indicated by a dashed line) with opposing marginal areas 206, 208 and 210, 212. As with the aforementioned central area 144 of block 100, the central area 204 of this block 160 will vary depending upon the particular configuration of the block and the extent to which the block is to be dressed.
As depicted, the block(s) 160 have had their marginal areas 206, 208 dressed, and no longer have the well defined angles formed by the marginal surfaces and the block contacting surfaces. As with block 100, the block 160 has a plurality of effective seals formed by the block contacting surfaces of adjacent blocks. That is, an effective seal is formed by block contacting surfaces 186 and 190, and another effective seal is formed by block contacting surfaces 188, 192. The block 160 is also provided with relief notches 196, 200 that isolate the block contacting surfaces 186, 188, and 190, 192, respectively, and prevent undesirable crack propagation.
Referring to
A brief description of a preferred method of dressing a plurality of marginal areas of an externally viewable surface of a masonry block will now be discussed. Initially, a person would first start by determining the environment and structure in which the block is to be used—an outdoor retaining wall, for example. Then, an appropriately configured, preformed block would be selected and the areas to be worked determined. The components of the first and second stations of the apparatus would then be adjusted, if need be, to reflect the dimensional characteristics of the preformed block and the areas of the externally viewable surface to be worked. For example, it may be necessary to lengthen or shorten the distance between the rotational axes of parallel chippers at the first and second stations in order to bring the chippers into the desired confronting relation to marginal areas of an externally viewable surface to be worked. Similarly, it may also be necessary to adjust the guide fences, stop, and block supports.
Dressing a block using the apparatus of the present invention may now proceed. First, the block is moved to the first station and positioned so that the externally viewable surface confronts the first pair of chippers. The block is then moved in a constrained manner towards the chippers until it reaches a stop. As the externally viewable surface of the block approaches the stop, the marginal areas enter the working field of the teeth, which dress the surface. Dressing of these marginal areas is essentially complete at the point where the externally viewable surface of the block contacts the stop. After the block has reaches the stop, the now partially dressed block is withdrawn from engagement with the chippers of the first station and moved to the second station.
At the second station, the block is positioned parallel to and laterally offset with respect to the rotational axes of the second pair of chippers. The position of the block is then adjusted so that the marginal areas of the externally viewable surface that are to be worked will fall within the working fields described by the rotating teeth of the chippers. After making the necessary adjustments, the block is then moved parallel to the rotational axes of the second pair of chippers in a constrained manner. As the marginal areas of the externally viewable surface enter the working fields of the chipper teeth, they are dressed, and after the block passes the second pair of chippers, the marginal areas of the block are now completely dressed.
It will be appreciated that there are ways other than the preferred method of dressing a masonry block. For example, there could be separate stations where each marginal area could be dressed separately. Or there could be one station where all of the work is done. In that vein, it will also be appreciated that the block could be relatively stationary and the tooling is movable with respect thereto.
The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| WO 02/092285 A2 | May 2001 | WO | international |
This is a continuation of application Ser. No. 10/477,878, filed Nov. 14, 2003, and published as U.S. publication number US 2004/0144378 A1 on Jul. 29, 2004, which is a national stage filing of PCT patent application No. PCT/US2001/015894, filed May 15, 2001, and published as WO 2002/092285 A2 on Nov. 21, 2002, all of which are hereby incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10477878 | Nov 2003 | US |
| Child | 12169433 | US |
